{
  "bibcode": "2014GCN.16183....1B",
  "body": "S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC), V. D'Elia (ASDC),\nJ. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),\nK. L. Page (U Leicester), M. H. Siegel (PSU) and\nE. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team:\n\nAt 13:13:28 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated SGR 1806-20 (trigger=597570).  Swift slewed immediately to the source. \nThe BAT on-board calculated location is \nRA, Dec 272.159, -20.404 which is \n   RA(J2000)  =  18h 08m 38s\n   Dec(J2000) = -20d 24' 12\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single spike\nwith a duration of about 0.128sec.  The peak count rate\nwas ~11,000 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 13:14:29.8 UT, 61.7 seconds after\nthe BAT trigger. Using promptly downlinked data we find an X-ray source\nwith an enhanced position: RA, Dec 272.1632, -20.4116 which is\nequivalent to:\n   RA(J2000)  = 18h 08m 39.16s\n   Dec(J2000) = -20d 24' 41.7\"\nwith an uncertainty of 3.8 arcseconds (radius, 90% containment). This\nlocation is 30 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at http://www.swift.ac.uk/sper. This\nposition is 3.1 arcsec from the known position of SGR 1806-20. No spectrum\nfrom the promptly downlinked event data is yet available to determine\nthe column density. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 63 seconds after the BAT trigger. No credible optical counterpart has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers 100% of\nthe XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nXRT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the large, but uncertain extinction expected. \n\nThe last previous detection of this Soft Gamma Repeater by \nBAT was on April 5, 2014.",
  "circularId": 16183,
  "createdOn": 1398778337000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "Trigger 597570: Swift detection of SGR 1806-20",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>"
}